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harness

v0.5.5

A file-backed, multi-sprint harness for long-running development, with separate Planner, Generator, and Evaluator roles.

CodexClaude Code3 Skills

By taiseiLicense: MIT0 GitHub starsUpdated last week

Directory evidence

Runtimes
Codex and Claude Code
Parsed components
3 skill or MCP entries
Source updated
Sep 12, 2026
Manifest status
Canonical path parsed

The directory validates manifest shape and source location. It does not execute the plugin or provide a security endorsement. Review the indexing methodology →

Install harness for Codex and Claude Code

Installs for the current user
codex plugin marketplace add mtaiseeei/agentic-harness
codex plugin marketplace upgrade agentic-harness-local
codex plugin add harness@agentic-harness-local

Paste and run these commands in a terminal with Codex. They add and refresh the agentic-harness-local catalog, then install this plugin.

Compatibility: the page URL and API slug “harness-4” remain stable.

  • Codex: harness-4@agent-plugin-marketplace → harness@agentic-harness-local

The installer fetches third-party code from the source repository shown on this page. This directory validates manifest structure and source location, but does not perform a security audit; review the manifest, components, and source before installing.

Get the source manually
git clone https://github.com/mtaiseeei/agentic-harness

Clone the source repository, then follow its setup instructions to add the plugin to a compatible client. The plugin root is plugins/harness/.

Plugin files

plugins/harness/
├── .codex-plugin/plugin.json
├── .claude-plugin/plugin.json
├── skills/grilling/SKILL.md
├── skills/harness-loop/SKILL.md
└── skills/using-harness/SKILL.md

Included Skills3

grillingskills/grilling/SKILL.md

Deeply examine a plan, decision, or idea through dependent questions. Use when the user requests grilling or Harness Planner selects it after assessing unresolved product decisions; not automatically for every planning request.

harness-loopskills/harness-loop/SKILL.md

Harness管理下で承認された開発をPlanner・Generator・独立EvaluatorとSprint正本で継続する。初期化・導入確認だけならusing-harnessへ。

using-harnessskills/using-harness/SKILL.md

新しいアプリ・まとまった機能開発、Harness管理repoの次Sprint・Patch、Harnessの初期化・導入確認の入口。監査や質問だけでは開発を開始しない。

Plugin manifests2

plugins/harness/.codex-plugin/plugin.json
{
  "name": "harness",
  "version": "0.5.5",
  "description": "A file-backed, multi-sprint harness for long-running development, with separate Planner, Generator, and Evaluator roles.",
  "author": {
    "name": "taisei",
    "url": "https://github.com/mtaiseeei"
  },
  "homepage": "https://github.com/mtaiseeei/agentic-harness",
  "repository": "https://github.com/mtaiseeei/agentic-harness",
  "license": "MIT",
  "keywords": [
    "harness",
    "planner",
    "generator",
    "evaluator",
    "agentic",
    "ai-orchestration"
  ],
  "skills": "./skills/",
  "interface": {
    "displayName": "Agentic Harness",
    "shortDescription": "Keep long-running development moving through file-backed sprints and independent evaluation.",
    "longDescription": "Agentic Harness starts from a short instruction and keeps substantial development moving across sessions. Three separate roles cover planning, generation, and independent evaluation; spec, sprint state, progress, and feedback files preserve the source of truth. When the host supports multiple agents, Harness uses them; otherwise it preserves role separation through independent work units. Use it for a new service, a business system, or the next sprint in an existing repository.",
    "developerName": "taisei",
    "category": "Productivity",
    "capabilities": [
      "Interactive",
      "Write"
    ],
    "defaultPrompt": [
      "Use Agentic Harness for this short new-service idea: make a file-backed multi-sprint plan and start the first sprint.",
      "Continue this existing repository from docs/sprints/state.md with separate Planner, Generator, and Evaluator roles."
    ]
  }
}
plugins/harness/.claude-plugin/plugin.json
{
  "name": "harness",
  "description": "A file-backed, multi-sprint harness for long-running development, with separate Planner, Generator, and Evaluator roles.",
  "version": "0.5.5",
  "author": {
    "name": "taisei"
  },
  "homepage": "https://github.com/mtaiseeei/agentic-harness",
  "repository": "https://github.com/mtaiseeei/agentic-harness",
  "license": "MIT",
  "keywords": [
    "harness",
    "planner",
    "generator",
    "evaluator",
    "agentic",
    "ai-orchestration"
  ]
}

For maintainers

If you maintain this plugin, link to this source-backed listing from your README so users can review its manifest and indexed components.

[harness on Agent Plugins Marketplace](https://pluginsmp.com/plugins/harness-4)